The invention deals with electric drives for driving axes within technical processes, according to the preamble of claim 1.
An electric automation system or an electric machine can comprise, in addition to many virtually wear-free electrical components, a large number of mechanical components that are subject to wear, such as gear mechanisms, toothed belts, brakes and guides. Attempts are primarily made to take precautions against the increasing wear by monitoring the characteristic variables that occur during operation. From the prior art, it is therefore known to draw conclusions about the mechanical loading from measured values which are derived from the instantaneous operating state of an electric drive. For instance, the temperature of the windings of an electric motor can be used to detect an increase in load and, if appropriate, to limit the motor current or to switch off the drive. The fault detection is carried out by means of limiting value monitoring or threshold value monitoring.
The disadvantage of these methods is that fault handling only becomes active when the fault has already occurred. The result of this is that the basic mechanical or electrical components may already have been stressed beyond the mark and therefore the wear progresses very quickly, given a frequent repetition of the fault.
Patents DE 196 14 748 C2 and DE 42 21 841 C1 deal with a fault diagnostic method and a monitoring control system for monitoring a plurality of devices. The latter document shows a control device for central monitoring, deviations of the operating data from the monitored devices being detected and processed further. The first-named document shows a relatively complex network with process computer nodes, diagnostic computers, control process computers and a large number of other peripherals for handling faults, specifically for application in electric drive systems as well.
On account of the complexity of the two arrangements, the result is quite complicated and therefore also costly solutions.